Brush holder



Dec. T8, 192s. 1,695,865

- H. c. SPECHT BRUSH HOLDER Filed March 10, 1927 INVENTOR WTNESSES: Wiw- Hans Cdpec/zif ATTORNEY Patented Dec. 18, 1928.

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Application filed much 16, m1. Serial No. 174,107.

My invention relates to brush-holding devices and articularly tobrush-holding devices for e ectric motors of the repulsion-inductiontype. g

In electric motors of the repulsion-induction type, it is frequentlydesirable to vary the posltion of the brushes relative to the comneutralaxis by rotating the brush-holding device in a circularhole provided inthe motor frame. As the siaeof such circular hole was limited by theavailable space, this construction necessitated the "disposition of thebrush at an angle, in order to obtain the desired angle or lead withrespect to the neutral axis. Various means for locking the brush-holdingdevice in this position have been provided, but have beenunsatisfactory, either becaum they did not provide apositive locking ar-1 rangementor because they were so complicatedthat they easily becameinoperative or were too expensive to manufacture.

By my invention", I provide a brush-holding device which is simple inconstruction and easy to manufacture. and which is provided with meansfor positively locking it in position. i

provide a brusholding device which comprises means for positioning thebrush ofa repulsion-induction motor on either side of the neutralosition, I I

Another object of'my invention is toprovide a device of theaboverharacte of such shape and design that the angle o contact betweenthe brush and the commutator may readily be variedTby simple changes inthe design without eiiecting the position of lead of the brush.

A further object of my invention is to provide a device of the abovecharacter which comprises simple means for positively securing thedevice against displacement in any direction except radially outward.

In the accompanying drawing,

Fig. 1 is a plan view of my invention,

Fig. 2 is a horizontal sectional view of the device taken along the line11-11 of Fig. 3,

' Fig. 3 is a. vertical sectional view of the device, 7 i I Fig. 4 is afra mentary View, in elevation, ofamotor embo ying my invention, and g1g. 5 is a plan view of a portion of the motor frame embodying minvention.

An approximately circu ar disk 1 is provided with a large, eccentricallydisposed, tubular, depending portion 2, and a small. auxiliarydependingportion 3, both of which extend substantially perpendicularlyto the plane of the'face of the disk. The large proectmg portion 2 isprovided with a perforation or chamber 4 extending longitudinallytherethrough, constituting a brush cartridge in which is disposed acarbon brush 5, a spring 6 for positioning the brush 5, and a iiexibleconductor member 7 shunting current around thespringfi. The brush 5 isslidably positioned in the chamber and is disposed in the lower portionthereof. The spring 6 is arranged to cooperate with the brush and tendsto expel the brush from the chamber. It will be understood that twobrushes 5 are utilized in a repulsion motor.

The upper portion of the chamber is enlarged and is provided with screwthreads 8 Y to receive a cap screw 9 for closing the end of the chamberg and maintaining the spring 6 in position. The cap screw 9 is providedwith a longitudinal cavity 11 extending into the lower portion thereof:Ametallic terminal 1-2, arranged to fit the cavity 11 and having I acylindrical, downwardly projecting boss 13 One of the o eets of myinvention is to is provided for makin connection between the flexibleshunt 7 an theframe of the motor; The projecting boss .13 of theterminal 12 is inserted ,in the upper end ofthe spring,

thereby ositionin the same andgrounding lhebru es 5 on t enframe. I

The smaller projecting portion '3 of the brush-holding device has acrosssection of substantially diamond shape, as shown in dotted lines in Fig.1, and is disposed diametrically opposite the larger projecting portion2. The extreme length of the cross section of the smaller projectingportion is made the same as the diameter of the larger projectingportion for purposes which will be subsequently disclosed.

Referring to Figs. 4: and 5, av portion of an electric motor 14 isshown. A flat boss 15, provided with two circular openings 16 isdisposed in the motor frame at the commutator end. The openings 16 areof the proper size and spacing to :mcommodate the two projectingportions 2 and 3 of the brush-holding device which secured in place bymeans of two machine screws 18 and 19 extending through small holes 21and. 22, in the diskshaped portion 1 and screwed into the tapped holes23 and 24-, in the motor frame 16. It is noted that the cover plate 1 issymmetrical with respect to two axes, one passing through the centers otthe two large holes 16, and the other at rig angles thereto and midwaybetween the said holes. The fastening screws 18 and 19 are syn'nnetricalwith respect to both axes. whereby the brushholder may be reversedthrough 180.

It will he unden'tood that two brushes are provided for repulsion motoroperation. li hen it is desir d to reverse the rotation of the motor bysh. i side of the neutral screws 18 and 19 are removed and the brushholder is lifted from its position in the boss 15. The larger projectingportion 2 is inserted in the opening in the boss formerly occupied bythe small projecting portion 3, and the smaller projecting portion 3 isinserted in the other opening in the hose, thereby bringing thebrush-holding device 17 into a position in which it is rotatedsubstantially 18 around the axis of the disk.

A raised arrow is provided in the upper face of the disk which indicatesthe direction oi? rotation of the motor.

In manufacturing this device, I am able to vary the angle of contactbetween the brush and the commutator without varying the distance of thepoint o't contact from neutral position. and vice versa. This isaccomplished by varying the distance between the two projecting portions2 and of the brushholder.

It will be apparent. from the above descri ption. that my device isextremely simple and. eas to manufacture and has relatively few paationand inexpensive to construct.

In addition, it apparent that the abovedescribed arrangement of partscauses the device to be firmly secured in position and maintainedagainst accidental displacement. In addition, it is very easy to reversethe angle of lead or the brush relative to the neutral point. since itis necessary merely to remove two screws.

thereby melting it dependable in oper- By utilizing a diamoml-shapecross-section for the smaller projecting portion 25, I: am able to makethe device more compact in design, as will be readily seen, withoutsacrilicing any strength or rigidity in the device. It is apparenthowever. that it would he possible to utilize various other shapes inthe corn struction of this device.

\Vhile I have described my invention. setting forth a specific exampleoi. the construction thereof. it is apparent that my invention notlimited to the details shown and described, and I desire that. theappended claims shall be given the broadest interpretation consistentwith their wording and the prior art.

I claim as my invention 1. In a dynamo-electric machine, a machine framehaving a plurality of openings therein, and a lDlllSll-llOlCllUQ deviceremovably mounted in the said frame and having a plurality ofprojections arranged to lit in the said openings, whereby the device ismaintained in any one of a plurality of positions.

In a dynamo-electric machine. a machine frame having a plurality ofopenings therein. a brush-holding device having a plurality oiprojecting portions arranged to lit the said openings, one of saidprojecting portions being hollow, and a brush slidably supj'iorted inthe said hollow projecting portion of: the device.

3. A motor having a frame, ln'ushholders and a commutator cylinder.charac ived by means for reversing the angle of lead of each brush withrespect to an axis of the motor.

said means comprising a portion ot the frame having two holes therein onopposit sides oi. said axis the brushholder comprising a cover plateextending over both of said ho es and having a downwardly extending hr1h cartridge extending thrmigh eithe one oi said holes. according to theposition o l he. brush.

4. A ln'ushholder comj'irising a cover plate which is syn'imetrical withl'tF l ltt'li to two axes, retaining means symmetrically dispo-rd withrespect to both of said axe whereby said brushholder may be reversedthrough 180. and an eccentrically disposed downwardly projecting brushcartridge.

In testimony whereof. I have hereunto s1 :hscribed my name this th dayof March. 102?.

HANS C. SPEC H 'I.

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